Cyclical restarts of the kube-dns-autoscaler pod

Issue descriptionIssue description

Updating Kubernetes and node groups from version 1.21 to version 1.22 triggered kube-dns-autoscaler cyclical restarts.

SolutionSolution

Sine we updated coredns and cluster-proportional-autoscaler, their notations changed, which is why the previous ConfigMap version is no longer valid.

Follow these steps to fix the issue:

1. Reduce the number of kube-dns-autoscaler replicas to 0:

   kubectl scale -n kube-system deploy kube-dns-autoscaler --replicas=0
   

2. Add the official cluster-proportional-autoscaler repository to your deployment:

   helm repo add cluster-proportional-autoscaler [https://kubernetes-sigs.github.io/cluster-proportional-autoscaler](https://kubernetes-sigs.github.io/cluster-proportional-autoscaler "External link (will open in a new window)")\
   helm repo update
   

3. Using our adapted values, install cluster-proportional-autoscaler:

   Installing cluster-proportional-autoscaler

   affinity: {}
   config:
   ladder:
     coresToReplicas:
       - [ 1, 1 ]
       - [ 64, 3 ]
       - [ 512, 5 ]
       - [ 1024, 7 ]
       - [ 2048, 10 ]
       - [ 4096, 15 ]
     nodesToReplicas:
       - [ 1, 1 ]
       - [ 2, 2 ]
   image:
     repository: registry.k8s.io/cpa/cluster-proportional-autoscaler
     pullPolicy: IfNotPresent
     tag:
   imagePullSecrets: []
   fullnameOverride:
   nameOverride:
   nodeSelector: {}
   options:
     alsoLogToStdErr:
     logBacktraceAt:
     logDir: {}
     logLevel:
     --v=6
     # Defaulting to true limits use of ephemeral storage
     logToStdErr: true
     maxSyncFailures:
     namespace: kube-system
     nodeLabels: {}
     #  label1: value1
     #  label2: value2
     pollPeriodSeconds:
     stdErrThreshold:
     target: deployment/coredns
     vmodule:
   podAnnotations: {}
   podSecurityContext:
     fsGroup: 65534
   replicaCount: 1
   resources:
     # We usually recommend not to specify default resources and to leave this as a conscious
     # choice for the user. This also increases chances charts run on environments with little
     # resources, such as Minikube. If you do want to specify resources, uncomment the following
     # lines, adjust them as necessary, and remove the curly braces after 'resources:'.
     limits:
       cpu: 100m
       memory: 128Mi
     requests:
       cpu: 100m
       memory: 128Mi
   securityContext: {}
     # capabilities:
     #   drop:
     #   - ALL
     # readOnlyRootFilesystem: true
     # runAsNonRoot: true
     # runAsUser: 1000
   serviceAccount:
     create: true
     annotations: {}
     # The name of the service account to use.
     # If not set and create is true, a name is generated using the fullname template
     # If set and create is false, no service account will be created and the expectation is that the provided service account already exists or it will use the "default" service account
     name:
   tolerations: []
   priorityClassName: ""
   

   helm upgrade --install cluster-proportional-autoscaler\
   cluster-proportional-autoscaler/cluster-proportional-autoscaler --values values-cpa-dns.yaml